1. Field of the Invention
The present invention relates to a magnetic disk drive that can be utilized as an external memory of a computer. More specifically, it relates to an electromagnetic read/write structure of a magnetic disk drive including at least one magnetic disk, the corresponding magnetic head, and the like. Further, it relates to the arrangement of various components of a magnetic disk drive within a disk enclosure.
2. Description of the Related Art
Generally, a magnetic disk drive, having a number of magnetic disks utilized as recording media, has been in practical use in various regions including computer networks as one of the promising non-volatile memory devices. Furthermore, in recent years, the fabrication of a magnetic disk drive that satisfies the demand for a disk drive that is compatible, compact, inexpensive, has a large storage capacity, is light weight and has lower power consumption, has been required and has been in demand.
To meet the above requirements, it is necessary for as many magnetic disks as possible to be assembled in a confined space, rather than increasing the surface density of recording media of magnetic disks by improving the characteristics of the magnetic head, magnetic medium per se, etc., so that mass storage can be attained without increasing costs for the development of the improved magnetic head. Also, even when many disks are assembled in the space, it is necessary for the size of the disk drive to be reduced as small as possible, so that effective space can be saved thereby promoting compactibility. When the magnetic disk drive is applied to a mobile-type computer, such as a portable lap-top personal computer, it also becomes necessary for the disk drive to withstand external impulse and external electromagnetic disturbance, and be lighter in weight and have a lower power consumption.
In a known magnetic disk drive according to the prior art, typically, a number of disks are arranged rotatably at high speed in a laminated manner with equally divided spaces and on the respective surfaces of the magnetic layers, recording media are formed concentrically. Further, in the vicinity of these disks, positioners are mounted and movable in the direction of the tracks of the disks, respectively, and supporting members are attached to the above positioners, respectively. Further, on the respective ends of the above supporting members, the reproducing/recording elements, e.g., magnetic heads are fixed in close proximity to the respective surfaces of the disks, so that the former can perform read/write operations for the tracks of the disks.
To be more specific, each of the above supporting members have an arm that is fixed on each of the positioners. The base end portion of each suspension element is fastened to the tip portion of each arm with screws. The above suspension element is formed by a bending process of an extremely thin stainless steel sheet. Further, on both sides of the suspension element, bent portions are formed respectively to ensure the stiffness of the above suspension element. Each magnetic head is attached to the tip portion of each suspension element, via a gimbal.
In such a construction of a magnetic disk drive, in order to increase the maximum sheets of disks that can be assembled in a given place within a disk enclosure, it seems reasonable that the thickness of the arms of supporting members should be decreased so that the distance between the surfaces of adjoining disks become shorter. However, when the above distance is too short, the bent portions of adjoining suspension elements are likely to interface and come into contact with each other. Therefore, it is difficult for the distance between the surfaces of adjoining disks to be reduced below a fixed value. Furthermore, since the thickness of each magnetic head or any other portion of a supporting member other than the bent portion is also necessitated to some degree, it becomes more difficult for the distance between the surfaces of adjoining disks to be reduced to a value less than the limited value (for example, 3 mm). Consequently, when the dimensions of the disk drive are predetermined, a disadvantage occurs in that the sheets of disks cannot be increased much more than the limited value known in the prior art. On the contrary, when the number of sheets of disks assembled are predetermined, another disadvantage occurs in that the thickness of the disk drive cannot be reduced less than the limited value also known in the prior art.
Furthermore, in the conventional 5 inch, 3.5 inch or 2.5 inch magnetic disk drive, a printed board of various controlling circuits is usually positioned separately from the disk enclosure including the magnetic head, disks, etc. Typically, the above printed board is fixed on the bottom surface of the disk enclosure, i.e., outside the disk enclosure (for example, see U.S. Pat. No. 5,025,335 (Frederick M. Stefansky)). Therefore, taking into account the thickness of the printed board, the height of the whole disk drive becomes more significant (for example, approximately 15 mm). Consequently, because of the thickness of the printed circuit board, it is further difficult to promote compactibility in the disk drive.
Further, last year a 1.8 inch disk drive was introduced by Integral Pheripherals Inc. The construction of the above disk drive is similar to that of other disk drives and the height of the former disk drive is also approximately 15 mm as a whole. Integral Pheripherals Inc. is further emphasizing that a thinner disk drive, as thin as 10 mm, can be realized by locating a printed circuit board on the side of a disk enclosure. In this case, though the thickness of the disk drive can be reduced, a new problem occurs in that the area of the disk drive including the printed circuit board and the disk enclosure is enlarged more than usual.